If you have been waiting to get one since they were out of stock recently - well, they are back in stock at Amazon, on sale for $621 with an additional $35 off coupon for a pre tax price of $586 shipped for prime members.
Update July 28-ish
They are in stock on the factory website for $610 delivered. No tax, free shipping for those without an Amazon Prime account and/or a Prime credit card. Code GX10OFF
I used my Amazon credit card for another 5% off, that almost covered the added sales tax for a net price delivered after the 5% on the card is applied of $593, about $10 less than buying it direct from the GX website (currently out of stock) with their free shipping, 10% off and no tax. I was growing annoyed at not being able to fill my guns or tanks to 4500 PSI so my extra/backup Yong Heng is going to one of my kids. I will use the other Yong Heng to bring stuff up to about 250 bar then finish them off with the GX CS4 to 300 / 310 bar for those that can handle it.
I wish the Hill EC3000 would do 400 bar and could run 5 hours without auto shutdown, but with a max of 300 bar it really doesn't make sense for my wants at $1300 to $1500 vs less than half that on the CS4.
Added July 26
I received my GX CS4 a few days ago and I am very impressed. If the CS4 existed when I bought my CS3 last year , I would have gone with the CS4 without question.
My main use for the CS4 is for filling guns / tanks that I want at 4500 psi and maybe some day higher than 4500 psi, which my Yong Heng can't handle even after the HP piston was rebuilt. It just hangs there at about 3300 fps no matter how long I run it once I hit "The Wall". No leaks anywhere on it.
So, just to see how it would do, I filled a newly purchased, used 30 minute / Scott SCBA from ZERO to 4500 PSI all in one go, bleeding the water on the CS4 about every 6-8 minutes. Total fill time was 2 Hrs 43 Minutes. The pump never overheated. Same temperature cooling air at 30 minutes as at 2:43. ( I didn't record the temp...sorry. Will next time. )
Conclusion? Since I usually buy expired tanks for use by me, family and friends and there is no filling service here anyway, I am comfortable filling 30 min / 45 cubic foot tank from empty the first time with the CS4, but I won't make that a routine. Instead I will take the empty tank up to 3000 PSI with the Yong Heng, then finish it off to 4500 with the CS4. It might be sketchy with a 45 min / 66 cu ft but doable based on a partial fill I did on one, but the 60 min / `88 cubic footer might be a bit too long for me. No plans to test a zero to 4500 psi fill on a 60 min SCBA.
The sound level is acceptable. Audible but not annoying if I am in the next room. If I am sitting next to it, I would be wearing earplugs or muffs. If it was running off a silent 12v power source, it would be even more quiet. Going to try that on a deep cycle batter on an AC charger soon.
I hit the 4-6 hr grease time and did one turn to grease it. Didn't notice any changes or drops in PSI like they say sometimes happens for a few minutes after greasing. Very easy to do. I did not open the grease reservoir to see how it works but will do that eventually. My cooling tank was spotless. I flushed it with distilled water several times and each time it came out clear. Running distilled and Ryslone Hy-Per cool. Will be changing to Water Wetter when it arrives.
(Note: I am going to post this at current end of this thread as well.)
Update July 28-ish
They are in stock on the factory website for $610 delivered. No tax, free shipping for those without an Amazon Prime account and/or a Prime credit card. Code GX10OFF
I used my Amazon credit card for another 5% off, that almost covered the added sales tax for a net price delivered after the 5% on the card is applied of $593, about $10 less than buying it direct from the GX website (currently out of stock) with their free shipping, 10% off and no tax. I was growing annoyed at not being able to fill my guns or tanks to 4500 PSI so my extra/backup Yong Heng is going to one of my kids. I will use the other Yong Heng to bring stuff up to about 250 bar then finish them off with the GX CS4 to 300 / 310 bar for those that can handle it.
I wish the Hill EC3000 would do 400 bar and could run 5 hours without auto shutdown, but with a max of 300 bar it really doesn't make sense for my wants at $1300 to $1500 vs less than half that on the CS4.
Added July 26
I received my GX CS4 a few days ago and I am very impressed. If the CS4 existed when I bought my CS3 last year , I would have gone with the CS4 without question.
My main use for the CS4 is for filling guns / tanks that I want at 4500 psi and maybe some day higher than 4500 psi, which my Yong Heng can't handle even after the HP piston was rebuilt. It just hangs there at about 3300 fps no matter how long I run it once I hit "The Wall". No leaks anywhere on it.
So, just to see how it would do, I filled a newly purchased, used 30 minute / Scott SCBA from ZERO to 4500 PSI all in one go, bleeding the water on the CS4 about every 6-8 minutes. Total fill time was 2 Hrs 43 Minutes. The pump never overheated. Same temperature cooling air at 30 minutes as at 2:43. ( I didn't record the temp...sorry. Will next time. )
Conclusion? Since I usually buy expired tanks for use by me, family and friends and there is no filling service here anyway, I am comfortable filling 30 min / 45 cubic foot tank from empty the first time with the CS4, but I won't make that a routine. Instead I will take the empty tank up to 3000 PSI with the Yong Heng, then finish it off to 4500 with the CS4. It might be sketchy with a 45 min / 66 cu ft but doable based on a partial fill I did on one, but the 60 min / `88 cubic footer might be a bit too long for me. No plans to test a zero to 4500 psi fill on a 60 min SCBA.
The sound level is acceptable. Audible but not annoying if I am in the next room. If I am sitting next to it, I would be wearing earplugs or muffs. If it was running off a silent 12v power source, it would be even more quiet. Going to try that on a deep cycle batter on an AC charger soon.
I hit the 4-6 hr grease time and did one turn to grease it. Didn't notice any changes or drops in PSI like they say sometimes happens for a few minutes after greasing. Very easy to do. I did not open the grease reservoir to see how it works but will do that eventually. My cooling tank was spotless. I flushed it with distilled water several times and each time it came out clear. Running distilled and Ryslone Hy-Per cool. Will be changing to Water Wetter when it arrives.
(Note: I am going to post this at current end of this thread as well.)
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